The proposed research is to develop new PZT/polymer composite transducer materials for improving the performance of the high frequency ultrasonic transducers. The proposed composites will combine the advantages of piezo ceramics and polymers to form (1-3) and (2-2) PZT/polymer composites. In the proposed research: (1) Nano PZT powder and organic filaments will be used to process fine diameter PZT fibers (~20 um), and fine fibers will be mixed with various polymers to form (1-3) composites; (2) PZT powders will be roll or shear formed to thin PZT plates (<30 um) and mixed with polymers to form (2-2) laminate composites. The proposed composites will offer oriented fiber or laminate structures which can improve ultrasound emission properties in a specific direction. The excellent flexibility of the composites leads to a reduction in service fatigue failure; a refined microstructure in the proposed (1-3) composite can improve imaging by allowing increased oscillation frequency of medical ultrasonic transducers; and light-weight composites offer advantages for man portable medical equipment. The proposed composites will be used as high frequency ultrasonic medical transducers for clinic diagnosis and drug delivery applications. PROPOSED COMMERCIAL APPLICATION: The potential medical applications of the proposed PZT/polymer composites are to high frequency ultrasonic transducers for imaging diagnosis and targeted drug delivery.